Oral irrigator

ABSTRACT

An oral irrigator has a pump, a discharge nozzle and a pressure control. The pump has a generally constant operating speed and feeds the discharge nozzle. The pressure control is adapted to modify a discharge pressure at the nozzle without a significant change in pump speed. The pressure control modifies a level of fluid flow restriction between the pump and the nozzle. The modification of the level of fluid flow restriction is accomplished by modifying aspects of a fluid flow path extending through the pressure control. The aspects modified include the diameter, length and/or number of direction changes of the fluid flow path.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation patent application of Ser. No. 11/483,376 now U.S. Pat. No. 7,670,141, filed Jul. 7, 2006 and entitled “Oral Irrigator,” the disclosure of which is hereby incorporated herein in its entirety.

TECHNICAL FIELD

The present invention relates to health and personal hygiene equipment and methods of controlling such equipment. More particularly, the present invention relates to oral irrigators and methods of controlling such equipment.

BACKGROUND

Oral irrigators for discharging a high-pressure fluid stream into a user's oral cavity are well known in the art and are useful for promoting oral hygiene and health. For example, a particularly effective oral irrigator is disclosed in U.S. patent application Ser. No. 10/749,675 which is hereby incorporated by reference in its entirety into the present application.

It is advantageous for an oral irrigator to discharge a fluid stream at a select pulse rate that is generally constant. For example, a particularly useful constant pulse rate is 1200 cycles per minute.

Depending on the user and the part of the oral cavity being impacted by the fluid stream, a high-pressure fluid stream or a low-pressure fluid stream may be preferred. Thus, it is preferable to offer oral irrigators with an ability to vary the pressure of the fluid stream discharging from the oral irrigator. Prior art oral irrigators have attempted to meet this need by adjusting pumping speed. Unfortunately, this approach results in an inability of the oral irrigator to provide a generally constant pulse rate.

SUMMARY

A handheld oral irrigator general includes a fluid reservoir, a pump, a pressure control assembly, and a nozzle. In an implementation disclosed herein, the pump may include a suction side and a discharge side. The suction side is in fluid communication with the fluid reservoir. The pressure control assembly may include a casing and a member displaceable within the casing. The casing has an inlet and an outlet. The inlet is in fluid communication with the discharge side of the pump, and the nozzle is in fluid communication with the outlet of the casing. In one embodiment, the member is longitudinally displaceable within the casing.

In some embodiments, the oral irrigator may also include an actuator for displacing the member within the casing. The member may have a portion that extends through the casing to couple to the actuator. In one embodiment, the portion of the member is an arm that extends through a longitudinally extending slot in the casing. A fluid flow path may extend from the inlet to the outlet and may be modifiable between a first route that extends along at least a portion of the member and a second route that does not.

In another implementation, an oral irrigator may have a pump, a discharge nozzle and a pressure control. The pump may have a generally constant operating speed and feeds the discharge nozzle. The pressure control may be adapted to modify a discharge pressure at the nozzle without a significant change in pump speed. The pressure control modifies a level of fluid flow restriction between the pump and the nozzle. The pressure control may modify the diameter of a fluid flow path extending through the pressure control. The pressure control may also modify the length of a fluid flow path extending through the pressure control. The pressure control may also modify the number of direction changes of a fluid flow path extending through the pressure control.

In a further implementation, an oral irrigator has a pump and a pressure adjustment assembly. The pump supplies a nozzle. The pressure adjustment assembly may be configured to provide a first fluid flow path associated with a high nozzle discharge pressure and a second fluid flow path associated with a low nozzle discharge pressure. The pressure adjustment assembly may be located between the pump and nozzle.

In one embodiment, the first fluid flow path offers a more direct route to the nozzle than the second fluid flow path. In another embodiment, the first fluid flow path has a length that is shorter than a length of the second fluid flow path. In a further embodiment, the second fluid flow path has a diameter that is smaller than a diameter of the first fluid flow path.

The pressure adjustment assembly may have a casing and a member displaceable within the casing. The casing defines a first orifice and the member a second orifice. The second fluid flow path extends through both orifices. The first fluid flow path extends only through the orifice of the casing.

In one embodiment, the pressure adjustment assembly may have a casing and a member displaceable within the casing. A portion of the second fluid flow path extends circumferentially about at least a portion of the member. The member may be generally cylindrical and define a groove extending about at least a portion of the circumferential outer surface of the member. The casing may define an inlet orifice that aligns with the groove to form a portion of the second fluid flow path. The member may also have a longitudinally extending center lumen in fluid contact with the groove via an orifice extending through a wall of the member.

In another implementation an oral irrigator may have a pump and a pressure adjustment assembly. The pump supplies a nozzle. The pressure adjustment assembly may have a first fluid flow friction setting associated with a high nozzle discharge pressure and a second fluid flow friction setting associated with a low nozzle discharge pressure.

In a further implementation, a method of controlling a nozzle discharge pressure of an oral irrigator having a pump that feeds a nozzle is described. The method includes modifying a fluid flow friction value of a fluid flow path between the pump and nozzle by modifying the fluid flow path. The fluid flow path may be modified by one or more of the following actions: changing its length, changing its diameter or by changing its number of direction deviations.

While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top isometric view of the handheld oral irrigator.

FIG. 2 is a top isometric view of the handheld oral irrigator.

FIG. 3 is a control side elevation of the handheld oral irrigator.

FIG. 4 is a reservoir side elevation of the handheld oral irrigator.

FIG. 5 is a right side elevation of the handheld oral irrigator as if viewed from the direction of arrow A in FIG. 3.

FIG. 6 is a left side elevation of the handheld oral irrigator as if viewed from the direction of arrow B in FIG. 3.

FIG. 7 is a top plan view of the handheld oral irrigator.

FIG. 8 is a bottom plan view of the handheld oral irrigator.

FIG. 9 is a section elevation of the handheld oral irrigator as taken along section line 9-9 in FIG. 4.

FIG. 10 is an isometric view of a motor side of the handheld oral irrigator with the outer housing of the handle portion removed to show the internal elements of the irrigator.

FIG. 11 is the same type of view as illustrated in FIG. 10, except of a pump side of the handheld oral irrigator.

FIG. 12 is a longitudinal section through the pump.

FIG. 13 is an isometric of view of the motor/pump/transmission arrangement with the rest of the irrigator 10 hidden for clarity purposes.

FIG. 14 is an isometric view of the pressure control valve assembly 85 with the majority of the rest of the handheld oral irrigator 10 hidden for clarity purposes.

FIG. 15 is a side elevation of the same elements depicted in FIG. 14, as viewed from the same direction as FIG. 6.

FIG. 16 is a side elevation of the same elements depicted in FIG. 14, as viewed from the same direction as FIG. 4.

FIG. 17A is a longitudinal cross section of the pressure control valve assembly as taken along section line 17-17 in FIG. 15 and wherein a spool is in a rearward location (i.e., a high discharge pressure position) within the valve cylinder.

FIG. 17B is the same view depicted in FIG. 17A, except the spool is in a forward location (i.e., a low discharge pressure position) within the valve cylinder.

FIG. 18A is a longitudinal cross section of the pressure control valve assembly as taken along section line 18-18 in FIG. 16 and wherein the spool is in a rearward location (i.e., a high discharge pressure position) within the valve cylinder.

FIG. 18B is the same view depicted in FIG. 18A, except the spool is in a forward location (i.e., a low discharge pressure position) within the valve cylinder.

FIG. 19 is a side view of the pressure control valve assembly as shown in FIG. 15, except the discharge tube, nozzle and control button are hidden for clarity purposes.

FIG. 20 is an isometric view of the valve assembly wherein the discharge tube, nozzle and control button are hidden for clarity purposes.

FIG. 21 is an isometric view of the spool and yoke.

FIG. 22 is an isometric latitudinal cross section taken along section line 22-22 in FIG. 15.

FIG. 23 is a similar view as illustrated in FIG. 10, except various components are shown in an alternate configuration.

FIG. 24 is a similar view as illustrated in FIG. 11, except various components are shown in an alternate configuration.

FIG. 25 is a bottom perspective view of a reservoir of the handheld oral irrigator.

FIG. 26 is a rear perspective view of a removable faceplate of the handheld oral irrigator.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, a handheld oral irrigator 10 allows a user to adjust the discharge pressure of the irrigator generated fluid stream while maintaining the pulse rate of the fluid stream. Thus, the handheld oral irrigator 10 is advantageous over the prior art because it allows a user to adjust the fluid stream discharge pressure to suit the user's comfort preference, while still allowing the oral irrigator to supply the fluid stream at a preferred or most effective pulse rate (e.g., 1200 cycles per minute).

For a discussion of the overall external configuration of one embodiment of the handheld oral irrigator 10, reference is made to FIGS. 1-8. FIGS. 1 and 2 are top isometric views of the handheld oral irrigator 10. FIG. 3 is a control side elevation of the handheld oral irrigator 10. FIG. 4 is a reservoir side elevation of the handheld oral irrigator 10. FIG. 5 is a right side elevation of the handheld oral irrigator 10 as if viewed from the direction of arrow A in FIG. 3. FIG. 6 is a left side elevation of the handheld oral irrigator 10 as if viewed from the direction of arrow B in FIG. 3. FIG. 7 is a top plan view of the handheld oral irrigator 10. FIG. 8 is a bottom plan view of the handheld oral irrigator 10.

As shown in FIGS. 1-7, in one embodiment, the irrigator 10 includes a handle portion 15 and a nozzle 20 with an orthodontic tip at its distal end. The nozzle 20 extends from a top end of the handle portion 15. The nozzle 20 is detachable from the handle portion 15 via a nozzle release button 25 located on the top of the handle portion 15.

As illustrated in FIGS. 1-6, in one embodiment, the handle portion 15 has a modified hourglass shape that gradually narrows from a wide base 30 (the proximal end of the irrigator 10) to a narrow gripping area 35 and gradually widens from the narrow gripping area 35 to a moderately wide top 40 (the distal end of the irrigator 10). The hourglass shape is aesthetically pleasing and ergonomically shaped to accommodate a user's hand, which in one embodiment will be a child or adolescent hand.

As indicated in FIGS. 1, 2 and 4-8, in one embodiment, the handle portion 15 includes a reservoir 45 that forms a part of the base 30. The reservoir 45 is removable from the rest of the handle portion 15 and includes a fill port 50 near the bottom of the reservoir 45. To fill the reservoir with fluid, the reservoir 45 may be disengaged and removed from the rest of the handle portion 15, the cap of the fill port 50 is opened, and a fluid is flowed into the reservoir 45 via the open fill port 50. Once the reservoir 45 is filled, the cap is closed on the fill port 50 and the reservoir 45 is reattached to the rest of the handle portion 15.

As can be understood from FIGS. 1, 2 and 4-8, the reservoir 45 may be filled while still attached to the rest of the handle portion 15. To do this, the cap of the fill port 50 is opened and a fluid is flowed into the reservoir 45 via the open fill port 50. Once the reservoir 45 is filled, the cap is closed.

For a discussion regarding disengaging the reservoir 45 from the rest of the handle portion, reference is made to FIGS. 8 and 25, wherein FIG. 25 is a bottom perspective view of the reservoir of the handheld oral irrigator. As best shown in FIGS. 8 and 25, the reservoir 45 includes a leaf spring latch 47 molded into a lower portion of the reservoir 45 to releasably secure the reservoir 45 to the handle portion 15. The leaf spring latch 47 is biased to engage the handle portion 15 when the reservoir 45 is joined with the handle portion 15. To disengage the leaf spring latch 47 from the handle portion 15, the user moves a latch portion 49 of the leaf spring latch 47 in the direction indicated by an arrow formed, printed, or placed on the leaf spring latch 47. In one embodiment, the reservoir 45 moves downwardly relative to the handle portion 15 when the leaf spring latch 47 is disengaged from the handle portion 15.

Referring again to FIGS. 1, 3 and 5-7 for a continued discussion of the overall external configuration of the handheld oral irrigator, in one embodiment, a control side of the gripping area 35 includes an on/off control 52, a pressure control 54, and a removable faceplate 56 that surrounds the locations of the two controls 52, 54. The on/off control 52 allows a user to turn on or shut off the irrigator 10. To turn the irrigator 10 on, the on/off control 52, which can be a slide, button, etc., is moved (e.g., slid or depressed) to complete an electrical circuit between the irrigator's internal power source and its motor. To turn the irrigator 10 off, the control 52 is moved again to break the electrical circuit.

The pressure control 54 allows a user to adjust the discharge pressure of a fluid stream discharging from the distal tip of the nozzle 20. In one embodiment, the nozzle release button 25 is located on the reservoir side opposite from the controls 50, 52, which helps limit accidental release of the nozzle 20 by accidental pressing or other engagement of the nozzle release button 25 when the user operates the controls 50, 52.

The removable faceplate 56 can be replaced with other faceplates having other colors or designs, thereby allowing the user to customize the appearance of the irrigator 10 as preferred. In one embodiment, the handheld oral irrigator 10 is sold or provided with multiple faceplates 56 of various designs and colors. The user selects their preferred faceplate and mounts it on the handle portion 15.

As shown in FIG. 26, which is a rear perspective view of the removable faceplate of the handheld oral irrigator, the removable face plate 56 has two or more L-shaped tabs 410 a, 410 b for receipt in corresponding slots or grooves defined in the handle portion 15 of the oral irrigator 10 to join the removable faceplate 56 to the handle portion 15. When joined together, the short legs of the tabs 410 a, 410 b are received in the slots or grooves defined in the handle portion 15 to maintain the joined relationship between the removable faceplate 56 and the handle portion 15.

To disconnect the removable faceplate 56 from the handle portion 15, the removable faceplate 56 is sufficiently flexible such that a user can deflect the edges 415, 420 of the removable faceplate 56 inward in order disengage the tabs 410 a, 410 b from the handle portion 15 to pull the faceplate 56 away from the handle portion 15. As a user moves the edges 415,420 of the removable faceplate 56 inwardly, the short legs of the tabs 410 a, 410 b are removed from the slots or grooves in the handle portion 15, thereby allowing the user to remove the removable faceplate 56 from the handle portion 15.

To join the removable faceplate 56 to the handle portion 15, a user deflects the edges 415,420 of the removable faceplate 56 inwardly and abuts a rear facing surface 425 of the removable faceplate 56 against the handle portion 15. When the removable faceplate 56 abuts the handle portion 15 in the proper location and orientation, the short legs of the tabs 410 a, 410 b generally align with the grooves or slots in the handle portion 15. In one embodiment, the handle portion 15 has a recessed surface surrounding the controls 50, 52 to aid a user in properly locating and orienting the removable faceplate 56 relative to the handle portion 15. Once the removable faceplate 45 abuts the handle portion 56 in the proper location and orientation, the user stops squeezing the edges 415, 420 of the removable faceplate inwardly, thereby causing the short legs of the tabs 410 a, 410 b, which are biased to move outwardly by the internal forces generated by inward movement of the edges 415, 420 of the removable faceplate 56, to enter into the grooves or slots defined in the handle portion 15.

Referring again to FIGS. 1, 3 and 5-7 for a continued discussion of the overall external configuration of the handheld oral irrigator, the reservoir side of the gripping area 35 includes a soft over molded grip area 58, which in one embodiment, includes gripping bumps 60, a textured gripping surface, or other grip enhancing features.

As illustrated in FIGS. 1 and 3, in one embodiment, a charging plug 63 exits in the handle portion 15 near the base 30. The charging plug 63 is used to place an external power source in electrical communication with an internal power source (e.g., battery) located within the handle portion 15.

For a discussion of the overall internal configuration of one embodiment of the handheld oral irrigator 10, reference is made to FIGS. 9-11, 23 and 24. FIG. 9 is a section elevation of the handheld oral irrigator 10 as taken along section line 9-9 in FIG. 4. FIG. 10 is an isometric view of a motor side of the handheld oral irrigator 10 with the outer housing 65 of the handle portion 15 removed to show the internal elements of the irrigator 10. FIG. 11 is the same type of view as illustrated in FIG. 10, except of a pump side of the handheld oral irrigator 10. FIG. 23 is a similar view as illustrated in FIG. 10, except various components are shown in an alternate configuration. FIG. 24 is a similar view as illustrated in FIG. 11, except various components are shown in an alternate configuration.

As shown in FIG. 9, the irrigator 10 includes an outer housing 65 that forms the exterior surface of the handle portion 15. The housing 65 encloses a motor 70, a pump 75, a transmission 77, a rechargeable NiCad battery 80, and a pressure control valve assembly 85. In one embodiment as illustrated in FIGS. 10 and 11, the motor 70 and pump 75 are located in a side-by-side arrangement near the base 30, the transmission 77 is located below the motor 70 and pump 75, the battery 80 is located above the motor 70 and pump 75, and the valve assembly 85 is located above the battery 80. In another embodiment as illustrated in FIGS. 23 and 24, the battery 80 is located near the base 30, the motor 70 and pump 75 are located above the battery 80, the transmission 77 is located above the motor 70 and pump 75, and the valve assembly 85 is located above the transmission 77. The transmission 77 couples the motor 70 to the pump 75 to convert the rotational output of the motor 70 into the longitudinally reciprocating movement of the pump's piston 120.

As illustrated in FIG. 9, the removable reservoir 45 forms a significant part of a lower side of the handle portion 15. The fill port 50 opens into the reservoir 45, and the reservoir 45 extends under a portion of the housing 65 enclosing the motor 70 and pump 75. A transfer tube 90 extends from a bottom level of the reservoir 45 to a seal coupling 95. In one embodiment, the transfer tube 90 is part of the reservoir. In another embodiment, the transfer tube 90 is separate from the reservoir 45. When the reservoir 45 is coupled to the rest of the handle portion 15, the seal coupling 95 sealing mates with a bottom end of a suction tube 100, which leads to a suction port 105 of the pump 75, as best understood from FIGS. 11 and 24. Thus, the reservoir 45 is placed in fluid communication with the suction side of the pump 75.

As indicated in FIGS. 10 and 11, and FIGS. 23 and 24, the motor 70, pump 75, transmission 77 and valve assembly 85 are coupled to a chassis plate 110 longitudinally extending through the housing 65 of the handle portion 15. In one embodiment, the controls 52, 54, motor 70 and the battery 80 are located on one side of the plate 110, and the pump 70 and valve assembly 85 are located on the other side of the plate 110.

As can be understood from FIGS. 9 and 11, the suction tube 100 is detachably sealably coupled to the seal coupling 95 by coupling the reservoir 45 to the rest of the housing 65 of the handle portion 15 such that the free end of the suction tube 100 is received in the seal coupling 95. As shown in FIG. 11, fluid traveling form the reservoir 45 to the distal end of the nozzle 20 is drawn through the transfer tube 90, into the suction tube 100 at the seal coupling 95 and to the suction port 105 of the pump 75.

As can be understood from FIG. 12, which is a longitudinal section through the pump 75, when a piston 120 moves rearwardly in a cylinder 115 of a cylinder casing 118 (rearward movement indicated by arrow X in FIG. 12), a discharge wafer 121 of a discharge wafer valve arrangement is forced against a discharge valve seat 122 and the fluid is drawn through the suction port 105 of a suction casing 107 of the pump 75, past a suction wafer 108 forming a suction wafer valve arrangement, and into the cylinder 115. When the piston 120 moves forwardly (as indicated by arrow Y in FIG. 12), the suction wafer 108 is forced against the suction valve seat 125 and the fluid is forced past the discharge wafer 121, into a discharge port 130 of a discharge casing 135 of the pump 75, and into a discharge tube 140 leading to the valve assembly 85, as illustrated in FIGS. 11 and 24.

In one embodiment, as depicted in FIGS. 11 and 12, the pump 75 is formed from three casings (e.g., the suction casing 107, cylinder casing 118 and discharge casing 135). In one embodiment, the three casings 107, 118, 135 are held together via a joining mechanism. For example, in one embodiment, a screw 145 (illustrated in FIG. 11) is received in screw receiving holes 146 (shown in FIG. 12) in the three casings 107, 118, 135.

For a discussion of the motor/pump/transmission arrangement, reference is made to FIG. 13, which is an isometric of view of the motor/pump/transmission arrangement with the rest of the irrigator 10 hidden for clarity purposes. As shown in FIG. 12, a pinion gear 150 extends from the motor 70 to drive a gear 155 carrying a cam 160. A piston rod 165 (see FIGS. 12 and 13) extends between the piston 120 and a cam follower end 170 of the piston rod 165. The cam follower end 170 receives the cam 160, and as the cam 160 is caused to rotate, the cam follower 170 and cam 160 act to convert the rotational movement of the motor 70 into longitudinal reciprocal displacement of the piston 120 within the cylinder 115.

For a discussion of the pressure control valve assembly 85, reference is made to FIGS. 14-22. FIG. 14 is an isometric view of the pressure control valve assembly 85 with the majority of the rest of the handheld oral irrigator 10 hidden for clarity purposes. FIG. 15 is a side elevation of the same elements depicted in FIG. 14, as viewed from the same direction as FIG. 6. FIG. 16 is a side elevation of the same elements depicted in FIG. 14, as viewed from the same direction as FIG. 4. FIG. 17A is a longitudinal cross section of the pressure control valve assembly 85 as taken along section line 17-17 in FIG. 15 and wherein a spool 180 is in a rearward location (i.e., a high discharge pressure position) within the valve cylinder 185. FIG. 17B is the same view depicted in FIG. 17A, except the spool 180 is in a forward location (i.e., a low discharge pressure position) within the valve cylinder 185. FIG. 18A is a longitudinal cross section of the pressure control valve assembly 85 as taken along section line 18-18 in FIG. 16 and wherein the spool 180 is in a rearward location (i.e., a high discharge pressure position) within the valve cylinder 185. FIG. 18B is the same view depicted in FIG. 18A, except the spool 180 is in a forward location (i.e., a low discharge pressure position) within the valve cylinder 185. FIG. 19 is a side view of the pressure control valve assembly 85 as shown in FIG. 15, except the discharge tube 140, nozzle 20 and control button 54 are hidden for clarity purposes. FIG. 20 is an isometric view of the pressure control valve assembly 85 wherein the discharge tube 140, nozzle 20 and control button 54 are hidden for clarity purposes. FIG. 21 is an isometric view of the spool 180 and yoke 190. FIG. 22 is an isometric latitudinal cross section taken along section line 22-22 in FIG. 15.

As can be understood from FIGS. 14-18B and 22, fluid pumped through the discharge tube 140 from the pump 75 enters an inlet 210 of the pressure control valve assembly 85. As depicted in FIG. 19 and FIG. 22, in one embodiment, to enter the valve cylinder 185, the fluid passes through slot openings 215 in the cylinder wall 220.

As can be understood from FIGS. 17A-18B, a spool 180 is located in the cylinder 185 and longitudinally displaceable within the cylinder 185. As illustrated in FIG. 21, the spool 180 is cylindrically shaped with a pair of arms 257 extending outwardly and rearwardly from a middle portion of the spool 180. A lumen 258 extends longitudinally through the length of the spool 180. The free ends of the arms 257 are received in pivot holes 259 in a yoke 261. The distal end of the spool 180 includes a pair of o-ring receiving grooves 260, a fluid groove 265 positioned between the o-ring grooves 260, and an orifice 275 extending between the fluid groove 265 and the lumen 270. The proximal end of the spool 180 includes an o-ring receiving groove 277.

As indicated in FIGS. 17A and 18A, when the spool 180 is located rearwardly in the cylinder 185, the fluid passes through the slot openings 215 (see FIGS. 19 and 20) and directly from the front of the cylinder 185, through the valve assembly outlet 225, through the lumen 230 of the nozzle 20, and out the distal tip of the nozzle 20 as a high discharge pressure fluid stream. As indicated in FIGS. 17B, 18B and 21, when the spool 180 is located forwardly in the cylinder 185, the fluid passes through the slot openings 215 (see FIGS. 19 and 20) and between the fluid groove 265 and the inner circumferential surface of the cylinder 185, through the orifice 275, into the lumen 258 of the spool 180, through the valve assembly outlet 225, through the lumen 230 of the nozzle 20, and out the distal tip of the nozzle 20 as a low discharge pressure fluid stream.

As can be understood from FIGS. 17A-20, when the spool 180 is in the forward position within the cylinder 185 (i.e., the low discharge pressure position), the fluid flow passing through the pressure control valve assembly 85 must overcome a substantially increased frictional resistance as compared to when the spool 180 is in the rearward position within the cylinder 185 (i.e., the high discharge pressure position). Accordingly, when the spool 180 is in the low discharge pressure position, the pressure control valve assembly 85 creates a substantially high-pressure drop in the fluid flow passing through the assembly 85 as compared to when the spool 180 is in the high discharge pressure position. Thus, without having to adjust the operating speed of the pump 75, a user may adjust the discharge pressure of a fluid stream emanating from the nozzle 20 of the oral irrigator 10 by adjusting the position of the spool 180 within the cylinder 185. Accordingly, the discharge pressure may be substantially modified by a user without causing a substantial change in the preferred pulse rate of the fluid stream.

As can be understood from FIGS. 17A-20, moving the spool 180 from the high discharge pressure position (see FIGS. 17A and 18A) to the low discharge pressure position (see FIGS. 17B and 18B) modifies, in several ways, the fluid flow path through the discharge pressure control assembly 85 and, as a result, the fluid flow path between the pump 75 and the nozzle 20. First, moving the spool 180 from the high to the low discharge pressure position increases the length of the fluid flow path because the flow is diverted about the fluid groove 265, through the orifice 275 and through the lumen 258 before the flow can pass through the cylinder outlet 225 to the nozzle 20. Second, moving the spool 180 from the high to the low discharge pressure position substantially decreases the diameters or flow areas of the fluid flow path because the diameters or flow areas of the fluid groove 265, orifice 275, and lumen 258 are substantially smaller than the internal diameter or flow area of the cylinder 185. Third moving the spool 180 from the high to the low discharge pressure position increases the number of direction deviations the fluid flow must undergo because the fluid must travel a tortuous route around the groove 265 and through the orifice 275 and lumen 258 before the flow can pass through the cylinder outlet 225 to the nozzle 20.

Each of these modifications to the fluid flow path brought about by moving the spool 180 from the high to low discharge pressure position increases the magnitude of the fluid flow friction between the pump 75 and the nozzle 20. Accordingly, although the pump 75 continues to operate at generally the same speed and provides a fluid stream at generally the same pulse rate, because the spool 180 moves from the high to the low discharge pressure position within the cylinder 185, the discharge pressure of the fluid stream at the distal end of the nozzle 20 decreases from a high to low discharge pressure.

Research has indicated that some fluid stream pulse rates are more effective than other pulse rates. For example, in one embodiment, the pump 75 of the oral irrigator 10 cycles at a rate such that it discharges a fluid stream out the nozzle 20 that has a pulse rate of 1000-1600 pulses per minute and, in one embodiment, 1100-1400 pulses per minute and, in one embodiment, 1200 pulses per minute. As discussed in U.S. Pat. No. 3,227,158 issued to Mattingly, which is incorporated by reference herein in its entirety, a pulse rate of 1000-1600 pulses per minute has been found to be the most effective pulse rates for the purposes of oral hygiene and health. Other highly effective pulse rates for the purposes of oral hygiene and health also include 1100-1400 pulse per minute and 1200 pulses per minute.

The pressure control feature is advantageous because it allows a user to adjust the fluid stream discharge pressure to suit the user's comfort preferences while maintaining the pulse rate generally at a preferred pulse rate. For example, regardless of whether the pressure control valve assembly 85 is set to cause a low or high discharge pressure fluid stream to emanate from the nozzle 20, the fluid stream will have a preferred number of pulses per minute (e.g., 1000-1600 pulses per minute, 1100-1400 pulses per minute, 1200 pulses per minute, etc.).

For a discussion of the cylinder's configuration, reference is again made to FIGS. 14 and 17A-20. As best understood from FIGS. 14, 19 and 20, the cylinder 185 of the pressure control valve assembly 185 includes a proximal portion 185 a received within a collar portion 185 b of a distal portion 185 c. A slot 300 extends longitudinally along the sides of the cylinder 185, and the arms 257 of the spool 180 extend through the slots 300 to couple with the arms of the yoke 261. As indicated in FIGS. 17A-18B, the cylinder 185 is hollow to receive the spool 180, and the proximal end of the cylinder proximal portion 185 c is walled-off such that when a fluid flows into the lumen 258 of the spool 180, the fluid impacts the proximal end of the cylinder proximal portion 185 c to establish a back pressure condition within the pressure control valve assembly 85. As can be understood from FIGS. 17A and 17B, the o-rings 260, 277 prevent fluid from escaping the cylinder 185 through the slots 300.

For a discussion of the linkage 305 used to cause the spool 180 to displace within the cylinder 185, reference is again made to FIGS. 9, 14, 15, 18A-21. As best understood from these figures, the linkage 305 includes the yoke 261 and the pressure control 54. The yoke 261 includes a pair of arms, and each arm has a pivot hole 259 near its free end. The pivot holes 259 pivotally receive therein the free ends of the spool arms 257. The yoke includes an arcuately slotted tongue 310 opposite the yoke arms for pivotally receiving therein a ball 315 extending from the pressure control 54.

As indicated in FIG. 9, in one embodiment, the pressure control 54 is a slide supported by the housing 65 of the handle portion 15 of the irrigator 10. As illustrated in FIGS. 19 and 21, the yoke 261 has a rocker portion 320 from which the tongue 310 extends. As shown in FIGS. 18A and 18B, the rocker portion 320 resides within a hole or slot 325 in the chassis plate 110, which allows the tongue 310 to rock towards the nozzle 20 or towards the base 30, depending on how the slide 54 is displaced along the housing 65.

As indicated in FIG. 18A, when the slide 54 is shifted towards the nozzle 20, the tongue 310 is rocked towards the nozzle 20 thereby causing the yoke 261 to pivot about the hole 325 in the chassis plate 110 such that the yoke arms move towards the base 30 and pull the spool arms 257 towards the base 30, which causes the spool 180 to move towards the base 30 (i.e., the spool 180 moves into the high discharge pressure position). As indicated in FIG. 18B, when the slide 54 is shifted towards the base 30, the tongue 310 is rocked towards the base 30 thereby causing the yoke 261 to pivot about the hole 325 in the chassis plate 110 such that the yoke arms move towards the nozzle 20 and pull the spool arms 257 towards the nozzle 20, which causes the spool 180 to move towards the nozzle 20 (i.e., the spool 180 moves into the low discharge pressure position).

For a discussion regarding the elements of the nozzle release, reference is again made to FIGS. 9, 14, 15 and 18A-20. As illustrated in these figures, the nozzle release button 25 is coupled to a collar 350 having an opening 355 centered about the hole 360 of the nozzle base receiving cylinder 368, which extends from the cylinder outlet 225. The proximal end of the nozzle 20 is received in the receiving cylinder 368 and the collar 350. The collar 350 is biased into a nozzle base groove 370 by a spring 380. The groove 370 extends about the circumference of the nozzle base. To release or disengage the collar 350 from the nozzle base groove 370 to allow the nozzle 20 to be withdrawn from the receiving cylinder 368, the nozzle release button 25 is depressed against the biasing force of the spring 380, which causes the collar 350 to shift out of engagement with the groove 370. The nozzle 20 is then withdrawn from the cylinder 368.

As can be understood from the preceding discussion, the oral irrigator of the present invention is advantageous because it allows a user to adjust the discharge pressure of the fluid stream emanating from the oral irrigator without bringing about a significant change in the pulse rate of the fluid stream. Thus, the oral irrigator can continue to supply a fluid stream at a preferred pulse rate regardless of the discharge pressure selected by the user.

Although the present invention has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. The invention is limited only by the scope of the following claims. 

What is claimed is:
 1. A handheld oral irrigator comprising a moveable member externally accessible to a housing of the oral irrigator and configured to adjust an output pressure of fluid discharge from the oral irrigator, the moveable member having a first joint member extending into the housing of the oral irrigator; a linkage coupled to the first joint member further comprising a second joint member moveably coupled to the first joint member; and a yoke coupled to the second joint member, the yoke defining a generally oblong aperture; and a linear valve moveably coupled to the yoke; wherein movement of the moveable member displaces the linear valve within a fluid pathway changing a length of the fluid pathway to adjust the output pressure of fluid discharge from the oral irrigator; and the first joint member comprises a spherical member.
 2. The handheld oral irrigator of claim 1, wherein the second joint member is configured to moveably couple to the first joint member by at least partially covering the spherical member.
 3. The handheld oral irrigator of claim 1, wherein the linear valve comprises at least one arm for coupling the linear valve to the yoke.
 4. The handheld oral irrigator of claim 3, wherein the linear valve comprises a protruding member extending therefrom and at least partially into the generally oblong aperture of the yoke, the protruding member being located near a free end of the at least one arm.
 5. The handheld oral irrigator of claim 1 further comprising a pump positioned within the fluid pathway configured to operate at a constant speed; and an outlet nozzle within the fluid pathway, wherein the linear valve is coupled between the pump and the outlet nozzle within the fluid pathway.
 6. The handheld oral irrigator of claim 1, wherein the linear valve comprises a first fluid pathway and a second fluid pathway, the first fluid pathway having a larger diameter lumen flow area than the second fluid pathway.
 7. The handheld oral irrigator of claim 6, wherein the second fluid pathway comprises a longer length than the first fluid pathway.
 8. A handheld oral irrigator, comprising a moveable member externally accessible to a housing of the oral irrigator and configured to adjust an output pressure of fluid discharge from the oral irrigator, the moveable member having a first joint member extending into the housing of the oral irrigator; a linkage coupled to the first joint member further comprising a second joint member moveably coupled to the first joint member; and a yoke coupled to the second joint member, the yoke defining a generally oblong aperture and comprising a rocker portion configured to allow the second joint member to move in a rocking manner about the first joint member of the moveable member; and a linear valve having at least one arm moveably coupled to the yoke; wherein movement of the moveable member displaces the linear valve within a fluid pathway changing a length of the fluid pathway to adjust the output pressure of fluid discharge from the oral irrigator; and the rocker portion of the yoke is positioned within an aperture in a chassis plate to allow for the rocking movement.
 9. A handheld oral irrigator, comprising a moveable member externally accessible to a housing of the oral irrigator and configured to adjust an output pressure of fluid discharge from the oral irrigator, the moveable member having a first joint member extending into the housing of the oral irrigator; a linkage coupled to the first joint member further comprising a second joint member moveably coupled to the first joint member; and a yoke coupled to the second joint member, the yoke defining a generally oblong aperture and comprising a rocker portion configured to allow the second joint member to move in a rocking manner about the first joint member of the moveable member; and a linear valve having at least one arm moveably coupled to the yoke; wherein movement of the moveable member displaces the linear valve within a fluid pathway changing a length of the fluid pathway to adjust the output pressure of fluid discharge from the oral irrigator; and the yoke is configured to displace in a direction opposite to that of the moveable member when the moveable member is displaced.
 10. A handheld oral irrigator comprising a constant speed pump configured to pump fluid from a reservoir into a fluid pathway; an outlet nozzle located at a terminal end of the fluid pathway; a valve located within the fluid pathway between the pump and the nozzle, the valve configured to alter a pressure of fluid discharge from the outlet nozzle; and a valve control mechanism coupled to the valve comprising a user accessible member; a linkage coupling the user accessible member to the valve, the linkage comprising a slotted tongue movably coupled to the user accessible member; and a yoke having a pair of arms, each arm having pivot holes configured to receive a portion of the valve, the yoke being configured to displace the valve; wherein movement of the user accessible member displaces the valve via the linkage changing a length of the fluid pathway between the pump and the outlet nozzle to alter the pressure of fluid discharge.
 11. The handheld oral irrigator of claim 10, wherein the valve displaces linearly; the valve comprises an arm that extends outward and parallel to a direction of the linear displacement of the valve; and the plurality of arms pivotally are coupled to the yoke of the linkage.
 12. The handheld oral irrigator of claim 10, wherein the yoke comprises a rocker portion rotationally positioned within an aperture of a chassis plate; and the yoke is configured to pivot about an axis fixed by the rocker portion.
 13. The handheld oral irrigator of claim 10, wherein the user accessible member comprises an external slide supported by a housing of the oral irrigator and an internal joint member that extends into the housing to couple with the linkage.
 14. The handheld oral irrigator of claim 13, wherein the internal joint member comprises a spherical member.
 15. The handheld oral irrigator of claim 14, wherein the user accessible member is linearly displaceable along the housing of the oral irrigator; and the linkage is configured to move in a rocking manner about the spherical member.
 16. The handheld oral irrigator of claim 15, wherein the valve displaces linearly in a direction generally opposite to a direction of displacement of the user accessible member.
 17. A handheld oral irrigator comprising a pump configured to provide fluid into a fluid pathway; an outlet at a terminal end of the fluid pathway; and a pressure adjustment assembly located within the fluid pathway, the pressure adjustment assembly comprising a linear valve providing a selectable plurality of fluid paths; a pressure control accessible externally to a housing of the oral irrigator to allow a user to select one of the plurality of fluid paths, the pressure control including a spherical joint member; and a linkage coupling the linear valve and the pressure control and configured to displace the linear valve upon displacement of the pressure control to select one of the plurality of fluid paths, thereby adjusting a discharge pressure of fluid exiting the oral irrigator, wherein the linkage further comprises a slotted tongue member moveably coupled to the spherical joint member; a yoke member pivotally coupled to the linear valve; and a rocker portion configured to provide an axis of rotation for the linkage. 